U.S. patent application number 10/862114 was filed with the patent office on 2005-12-08 for interior contour for bore of a friction support bearing of a railway locomotive traction motor.
Invention is credited to Bien, Paul, Foster, Robert B., Macklin, John E..
Application Number | 20050268811 10/862114 |
Document ID | / |
Family ID | 35446273 |
Filed Date | 2005-12-08 |
United States Patent
Application |
20050268811 |
Kind Code |
A1 |
Bien, Paul ; et al. |
December 8, 2005 |
Interior contour for bore of a friction support bearing of a
railway locomotive traction motor
Abstract
A contour or profile of a bore of a locomotive traction-motor
support bearing structure, where such profile preserves the
currently center-loading of the upper load zone but moves inboardly
the lower load zone to a more general central location. The profile
of the bore for the support bearing, according to the invention,
takes into account not only truck-axle bending due to locomotive
weight, but also that from motor tilt through bearing clearances,
and couple action on the axle from heavy radial loads on PE support
bearing and adjacent axle gear. The bore is configured such that
the upper surface is horizontal, but the lower surface slopes
downwardly in the outboard direction at an angle based on a
function dependent upon the three misalignment factors. In a
preferred embodiment, the bore mid-section is defined as a
frustroconical section of a cone with an altitude having a slope of
substantially 1.times.M1 to the horizontal, and an apex angle of
substantially arc tan 2.times.M1, where M1 is the value of the
misalignment factor associated with the locomotive load on the
axle.
Inventors: |
Bien, Paul; (Downers Grove,
IL) ; Foster, Robert B.; (Erie, PA) ; Macklin,
John E.; (Fremont, NE) |
Correspondence
Address: |
Milton S. Gerstein
Much Shelist Freed
Suite 1800
191 N. Wacker Drive
Chicago
IL
60606
US
|
Family ID: |
35446273 |
Appl. No.: |
10/862114 |
Filed: |
June 3, 2004 |
Current U.S.
Class: |
105/199.4 |
Current CPC
Class: |
F16C 17/02 20130101;
F16C 2326/10 20130101; F16C 2240/30 20130101; B61C 9/38 20130101;
F16C 23/041 20130101; F16C 2240/40 20130101 |
Class at
Publication: |
105/199.4 |
International
Class: |
B61C 001/00 |
Claims
What is claimed is:
1. In a locomotive traction-motor support bearing having a bore for
mounting the traction motor to a truck-axle journal, said bore
having an upper surface section and a lower surface section, each
said upper surface section and said lower surface section defining
a middle portion thereof; said middle portion of said upper surface
section being substantially horizontal, and said middle portion of
said lower surface section having a downward slope in the outboard
direction, wherein the improvement comprises: said downward slope
of said middle portion of said lower surface section having a value
based on the values of at least the lower load-bearing misalignment
factors of: locomotive weight M1, motor tilt and skewing M2, and
couple-action M3 on the truck-axle.
2. The locomotive traction-motor support bearing according to claim
1, wherein said slope is approximately equal to 2.times.M1.
3. The locomotive traction-motor support bearing according to claim
2, wherein said middle portions are defined as the frustroconical
section of a cone with an altitude having a slope of substantially
1.times.M1 to the horizontal, and an apex angle of substantially
arc tan 2.times.M1.
4. The locomotive traction-motor support bearing according to claim
1, wherein said middle portions are defined as the frustroconical
section of a cone with an altitude having a slope of substantially
1.times.M1 to the horizontal, and an apex angle of substantially
arc tan 2.times.M1.
5. The locomotive traction-motor support bearing according to claim
1, wherein said slope is approximately equal to 0.002
inch/inch.
6. The locomotive traction-motor support bearing according to claim
4, wherein said slope of said middle portion of said lower surface
section is approximately equal to 0.002 inch/inch.
7. In a locomotive traction-motor support bearing having a bore for
mounting the traction motor to a truck-axle journal, said bore
having an upper surface section and a lower surface section, each
said upper surface section and said lower surface section defining
a middle portion thereof; said middle portion of said upper surface
section being substantially horizontal, and said middle portion of
said lower surface section having a downward slope in the outboard
direction, wherein the improvement comprises: said downward slope
of said middle portion of said lower surface section having a value
of approximately 2.times.M1, where M1 is the value of the
locomotive-weight misalignment factor.
8. The locomotive traction-motor support bearing according to claim
7, wherein said middle portions are defined as the frustroconical
section of a cone with an altitude having a slope of substantially
1.times.M1 to the horizontal, and an apex angle of substantially
arc tan 2.times.M1.
9. The locomotive traction-motor support bearing according to claim
7, wherein said downward slope of said middle portion of said lower
surface section is a function of misalignment M, .function.(M),
wherein .function.(M) is at least directly correlated with values
of at least two factors of misalignment, one said factor of
misalignment being caused by locomotive weight, and one said factor
of misalignment being caused by couple-action on the
truck-axle.
10. The locomotive traction-motor support bearing according to
claim 9, wherein .function.(M) is also directly correlated with the
value of an additional factor of misalignment caused by motor tilt
and skewing due to bearing clearances.
11. In a locomotive traction-motor support bearing having a bore
for mounting the traction motor to a truck-axle journal, said bore
having an upper surface section and a lower surface section, each
said upper surface section and said lower surface section defining
a middle portion thereof; said middle portion of said upper surface
section being substantially horizontal, and said middle portion of
said lower surface section having a downward slope in the outboard
direction, wherein the improvement comprises: said downward slope
of said middle portion of said lower surface section is a function
of misalignment M, .function.(M), wherein .function.(M) is at least
directly correlated with values M1 and M2, where M1 is misalignment
caused by locomotive weight, and M2 is misalignment caused by motor
tilt and skewing due to bearing clearances.
12. The locomotive traction-motor support bearing according to
claim 11, wherein .function.(M) is also directly correlated with
value M3, where M3 is misalignment caused by couple-action on the
truck-axle
13. The locomotive traction-motor support bearing according to
claim 11, wherein said slope is approximately equal to
2.times.M1.
14. The locomotive traction-motor support bearing according to
claim 11, wherein said middle portions are defined as the
frustroconical section of a cone with an altitude having a slope of
substantially 1.times.M1 to the horizontal, and an apex angle of
substantially arc tan 2.times.M1.
15. The locomotive traction-motor support bearing according to
claim 14, wherein said slope is approximately equal to 0.002
inch/inch.
16. In a support bearing having a bore for receiving an axle
element means, said bore having an upper surface section and a
lower surface section, each said upper surface section and said
lower surface section defining a middle portion thereof, the
improvement comprising: said middle portion of said upper surface
section being substantially horizontal, and said middle portion of
said lower surface section having a downward slope as a function of
misalignment M, .function.(M), wherein .function.(M) is directly
correlated with at least misalignment values M1 and M2, where M1 is
misalignment caused by load-weight on said axle, and M2 is
misalignment caused by motor tilt and skewing due to support
bearing clearances.
17. The support bearing having a bore for receiving an axle element
means according to claim 16, wherein said slope is at least
approximately equal to 2.times.M1.
18. The locomotive traction-motor support bearing according to
claim 16, wherein said middle portions are defined as the
frustroconical section of a cone with an altitude having a slope of
substantially 1.times.M1 to the horizontal, and an apex angle of
substantially arc tan 2.times.
19. In a support bearing having a bore for receiving an axle
element means, said bore having an upper surface section and a
lower surface section, each said upper surface section and said
lower surface section defining a middle portion thereof, the
improvement comprising: said middle portion of said upper surface
section being substantially horizontal, and said middle portion of
said lower surface section having a downward slope as a function of
misalignment M, .function.(M), wherein .function.(M) is directly
correlated with misalignment value M1, where M1 is misalignment
caused by load-weight on said axle; said downward slope of said
middle portion of said lower surface section having a value of
approximately 2.times.M1.
20. The support bearing having a bore for receiving an axle element
means according to claim 19, wherein said middle portions are
defined as the frustroconical section of a cone with an altitude
having a slope of approximately 1.times.M1 to the horizontal, and
an apex angle of approximately arc tan 2.times.M1.
21. The support bearing having a bore for receiving an axle element
means according to claim 19, in combination with a locomotive
traction motor, said support bearing being used in mounting said
traction motor to an axle journal of a locomotive truck; said
support bearing being capable of mounting said traction motor to
both the pinion end and commutator end, whereby said support
bearing may be used interchangeably either at the heavily loaded PE
position or the lightly loaded CE position without adversely
bearing performance at said CE position.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention is directed to a railway locomotive
traction motor and, in particular, to the friction support bearing
by which the traction motor is partially supported on the axle of
the railway truck mounting the underside of the locomotive, and, in
particular, to a method of customizing the geometry or bore-profile
of a traction motor support-bearing bore in order to optimize
alignment with the locomotive axle journal under heavy load
conditions, and to thus increase bearing load capacity and bearing
life under heavy load conditions.
[0002] Proper alignment between the support bearing and the truck
axle journal is important for maintaining good bearing performance,
because it provides maximum contact between journal and bearing to
thus insure minimum unit loading (lbs/sq.in.). This allows the
bearing to carry heavier radial loads or the same radial load with
greater reliability. This applies to both pinion end (PE) and
commutator end (CE) bearings, although it is not as important at
the CE position because of the light radial loading at this
location.
[0003] It is, also, common practice to use the same type of support
bearing for both the pinion end and commutator end. Thus, since the
greater radial load occurs at the pinion end, such a support
bearing must be so designed so as to withstand the greater wear at
the pinion end. This current parts-interchangeability requirement
of support bearings for use at either pinion end or commutator end,
therefore, results in a bearing which is acceptable for either
position, but optimum for neither position. Therefore, it is
current practice to use identical support bearings at both the
heavily loaded PE position and the lesser-loaded CE position for
locomotive traction motors equipped with plain friction bearings.
Thus, when providing a new type of bore for a support bearing for a
locomotive truck axle, ideally one would optimize the bearing bore
for the misalignment conditions existing at the PE position, and do
this in a way which allows continued use at the CE position, even
though not optimized for that lesser-loaded bearing position.
[0004] The primary cause of support bearing misalignment is bending
due to locomotive weight, and this factor alone theoretically
should tend to cause the upper load zone of the support bearing to
move an in inboard direction away from the center position of the
support-bearing bore, while also causing the lower load zone
thereof to move to an outboard location away from the center
position of bore. However, in actual use, it has been found that
such does not actually occur at the PE; instead, it has been found
that upper load zone remains generally centrally-located while the
lower load zone does move off-center toward the outboard end of the
support bearing. The problem has been to understand why this
occurs, and then to develop a bore-contour or profile consistent
with the findings as to the additional bending torques present
causing the shift of the load zones from the expected, which
contour will preserve the existing ideal location of the upper load
zone while moving the lower zone into a central position.
[0005] In U.S. Pat. No. 4,940,002, which is incorporated by
reference herein, there is disclosed a friction support bearing
having, in a first version, a skewed or tilted internal bore
design, which bore design more accurately positions the truck axle
journal therein during heavy load conditions. This prior-art bore
design takes into consideration the torque and bending loads of the
truck axle arising from the laterally-spaced radial forces
emanating from the weight of the locomotive acting on the journal
box bearings at the end of the axle and the reactive force of the
rail track acting on the wheel mounted by the axle, which bending
of the axle directly causes misalignment of the axle portion
extending through the traction-motor friction support bearing with
the bore of the support bearing. This misalignment causes excessive
loading and wear of the support bearing on the pinion-end thereof
adjacent the axle's drive gear. However, while this prior-art
bore-design may help to alleviate some excessive load concentration
on the pinion-end of the support bearing, it has not completely
solved the problem. In a second version U.S. Pat. No. 4,940,002,
there is disclosed forming the interior bore as variable or
changing conical sections, where there are actually four separate
conical sections employed. In this second version, there is
provided an upper central portion of the bore that is a
substantially horizontal line or surface, when viewed in vertical
cross section, while the lower or bottom central portion of the
bore is somewhat sloped.
[0006] The loading of a typical, prior-art traction-motor
pinion-end support bearing having a standard cylindrical bore
without the improved bore-profile of above-mentioned U.S. Pat. No.
4,940,002, is shown in FIG. 1. For best overall performance and
life of a traction-motor support bearing 10, the load zones for
loading the truck axle should be centered. This is so in order that
the lubricant entering the interior of the bearing via a wick
window 12 lubricates all contacting surface-areas, which wick
lubricator contacts the axle's journal through the window. In
addition, both load zones should be contained within the total
axial dimension of the wick if at all possible, again to ensure the
best possible lubrication. The example shown in of FIG. 1 is for
plain friction support bearings from traction motors with 8"
nominal diameter axles, with approximately 60,000 to 70,000 pounds
axle load and standard gauge wheel spacing. This combination of
parameters has an axle bending slope of about 0.001 inch/inch at
the mid-length portion of the PE bearing. Each PE traction-motor
support bearing 10 has two load zones, an upper 14 and a lower 16,
and these tend to be heaviest around 25.degree. from vertical
because of commonly-used 25.degree. gear-tooth pressure angle. Both
load-contact patterns can be seen in the window half of the PE
bearing with the upper load pattern above the lubricator
access-window and the lower load pattern below the window. The
axial location of these contact-patterns is of particular interest,
since it is key to understanding the misalignment existing between
the axle-journal and the support bearing. It may be seen in FIG. 1
that the upper load contact-pattern is well centered in the bearing
length, while the lower load contact-pattern is displaced
outwardly, or outboardly toward the bearing flange. Ideally, both
upper and lower load contact-patterns should be centered at
mid-length of the window, in order that the wick lubricator, which
contacts the journal through the window, provides the best possible
lubrication. Further, both load contact-patterns should be
contained within the total axial dimension or limits of the wick
lubricator if at all possible, again to ensure the best possible
lubrication. As may be seen in FIG. 1, only the upper load zone is
centered.
[0007] While used prior-art cylindrical-bore bearings have
exhibited an upper load-zone 14 that is centered, such is not the
case for the lower load-zone 16, which is skewed toward the
outboard end, or bearing flange. Both load zones 14, 16 are
actually visible in the window half of a PE bearing, with the upper
load zone above the window and the lower load zone below the
window. The above-described and shown load-patterns have been
observed on General Motor's Electric Motor Division (EMD) traction
motors, such as that disclosed in above-mentioned U.S. Pat. No.
4,940,002, with 8" diameter axles and standard gauge wheel
spacing.
[0008] Neither version disclosed in above-mentioned U.S. Pat. No.
4,940,002 is effective in solving the misalignment of the lower
load zone 16. This is so since the bore-profile of U.S. Pat. No.
4,940,002 only takes into account axle-bending torques associated
with locomotive weight. However, according to the present
invention, it has been discovered that other loads and torques are
present that cause axle-bending and concomitant load-bearing
misalignment, which hitherto have not been taken into account into
the consideration of a traction-motor support-bearing bore
profile.
SUMMARY OF THE INVENTION
[0009] It is a primary objective of the present invention to
provide an improved interior contour or profile for a friction
support bearing of a locomotive traction motor that more
realistically takes into account all bending moments of the truck
axle on which the traction motor is partially mounted, in order to
minimize or eliminate misalignment between the support bearing bore
and the truck-axle journal, and thus the misalignment of the upper
and lower load zones of the support bearing. It is also a primary
objective of the present invention to maintain the generally
centralized location of the upper load zone of a friction support
bearing of a locomotive traction motor exhibited by presently-used
support bearings, while better aligning the lower load zone thereof
to a central, or more central, location.
[0010] It is also a primary objective of the present invention to
achieve an interior bore-contour or profile for a friction support
bearing of a locomotive traction motor such that such profile may
also, under certain circumstances, be used for the bore of a
commutator-end (CE) friction support bearing without adversely
affecting the performance of the CE support bearing, whereby one,
standard, traction-motor friction support bearing may be used and
stocked for either the PE or CE end of the traction motor support
structure
[0011] It is also a primary objective of the present invention to
achieve an interior bore-contour or profile for a friction support
bearing of a locomotive traction motor such that such profile
thereof takes into account torques forces associated with the
causing of the bending of the truck axle that include axle bending
due, not only from locomotive weight, but also those derived from
motor tilt through bearing clearances and couple action on the axle
deriving from the heavy radial loads on the PE support bearing and
the laterally-juxtapositioned axle gear engaged with the pinion
gear of the traction motor at the PE end thereof.
[0012] According to the present invention, the contour or profile
for the bore of a locomotive traction-motor support bearing
structure is an improvement over that disclosed in U.S. Pat. No.
4,940,002, and is such as to preserve the currently-centered
loading for the upper load zone but to move inboardly the lower
load zone to a more general central location. The profile of the
bore for the support bearing, according to the invention, takes
into account not only truck-axle bending due to locomotive weight,
but also that from motor tilt through bearing clearances, and
couple acting on the axle from heavy radial loads on PE support
bearing and adjacent axle gear. According to the invention, it has
been discovered that the latter two axle-bending factors counteract
the first factor in the upper load-bearing zone, which has
accounted for the generally centrally-located positioning of the
upper load zone, as described above. In contrast, however, the
latter two axle-bending factors combine with the first axle-bending
factor to increase misalignment in the lower load-bearing zone;
hence, the observed outboard-direction misalignment of the lower
load-bearing zone described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention will be more readily understood with reference
to the accompanying drawings, wherein:
[0014] FIG. 1 is an isometric view of a typical, PE window half,
used, prior-art, locomotive traction-motor pinion-end support
bearing having a cylindrical bore and showing the locations of the
upper and lower load-bearing zones thereof;
[0015] FIG. 2A is a diagram showing all the additional torques
acting in a vertical plane on the locomotive truck axle causing
bending moments that affect the location of the upper load zone of
a locomotive truck friction support bearing;
[0016] FIG. 2B is a diagram similar to FIG. 2B but showing all the
additional torques acting in a vertical plane on the locomotive
truck axle causing bending moments that affect the location of the
lower load zone of a locomotive truck friction support bearing;
and
[0017] FIG. 3 is a sectional view showing the contour of bore of
the support bearing of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Referring now to the drawings in greater detail, the bore
design for the friction support bearing of the invention is
intended, in the preferred embodiment, for use with a locomotive
traction-motor manufactured by the Electric Motor Division of
General Motors Corporation, as disclosed in above-discussed U.S.
Pat. No. 4,940,002. This traction motor has a pinion-end friction
support bearing with a bore for passing therethrough the lubricated
axle-journal by which the traction motor is partially mounted to
the truck. The traction motor is also partially supported by the
friction support bearing at the commutator end, and by direct
mounting to the transoms of the truck through a resilient
suspension. This locomotive traction-motor is used with a railway
locomotive having an eight-inch axle and standard gauge
wheel-spacing, and approximately 60,000-70,000 pounds of axle load,
and which has exhibited an approximately 0.001 inch/inch
axle-bending slope at the mid-length of the PE support bearing due
to locomotive weight alone. As discussed hereinabove, the
bore-design of U.S. Pat. No. 4,940,002 only takes into
consideration the effects on axle-bending from locomotive weight.
However, it has been discovered that other factors contribute to
axle-bending which have not been taken into account by the
bore-design in this patent. These other factors have been
discovered to be the combined effects of motor tilt and skewing
because of bearing clearances, "couple" acting on the axle because
of the heavy radial loads on PE support bearing and the adjacent
axle-gear thereat, and also axle-bending due to tractive-effort
forces and gear-separating forces acting in the horizontal
plain.
[0019] Referring now to FIGS. 2A and 2B, misalignment caused by the
axle-bending forces or torque caused by the locomotive weight is
indicated by reference symbol M1; misalignment caused by motor tilt
and skewing through bearing clearances is indicated by reference
symbol M2; that caused by "couple" acting on the axle from heavy
radial loads on the PE support bearing and adjacent axle gear is
indicated by reference symbol M3. Axle-bending caused by
tractive-effort forces and gear-separating forces acting in the
horizontal plain have, for all intents and purposes, been ignored,
however, with only the major factors causing misalignment in the
vertical plane having been considered, which is the dominant plane
of misalignment. The misalignment M1 caused by locomotive weight
derives from the horizontal spacing between the forces F1 and F2
created by the locomotive weight acting on the journal box 20 and
the reaction force acting on the wheel 22 from the rail. The second
factor causing misalignment M2 derives from the simple tilting and
skewing of the motor 30 because of bearing clearances.
[0020] The third factor causing misalignment M3 caused by couple
derives from the horizontal spacing between the vertical forces F3
and F4 acting on the support bearing 24 from the heavy radial loads
and the juxtapositioned driven axle-gear 26 that is driven by the
traction motor's pinion gear
[0021] FIGS. 2A and 2B show the relative deflections and principle
loading of the locomotive axle in a vertical plane for both forward
and reverse directions, and both modes of operation, which are the
power mode and dynamic-brake mode, which dynamic-brake mode is
accomplished via the traction motor itself. The sense, or angular
direction, of these components of total misalignment varies with
direction of operation and whether in power mode or dynamic-brake
mode of locomotive operation. FIG. 2A shows the factors effecting
misalignment in the upper load zone (14 in FIG. 1), while FIG. 2B
shows the same for the lower load zone (16 in FIG. 1). It is to be
understood that the factors causing misalignment in the power mode
in the one direction would be of similar value and sense, or
angular direction, as in the dynamic-brake mode in the opposite
direction, as indicated in FIGS. 2A and 2B. Thus, the force vectors
shown in FIG. 2A for M2 apply to the power mode in forward
operation or to the dynamic-brake mode in the reverse direction.
The force vectors shown in FIG. 2B apply to the power mode in the
reverse operation or to the dynamic-brake mode in the forward
direction. The same holds true for misalignment contributor M3.
[0022] In FIGS. 2A and 2B, the misalignment M1 from locomotive
weight has been assigned a positive, or "+", sense to the
misalignment slope at the midpoint of the PE bearing. Considering
the other two dominant factors of misalignment in the vertical
plane, misalignment M2, which is the effect of motor tilt in
bearing clearances, and M3, the effect of couple created by
adjacent gear and support bearing loads, these have been assigned
either "+" or "-" sense according to whether these components add
to, or reduce, the misalignment caused by axle-bending,
respectively. Thus, in FIG. 2A, since these factors M2 and M3
counteract torque M1 for the upper load-zone, and thereby reduce
misalignment, they have been indicated as negative values. However,
in FIG. 2B, since factors M2 and M3 add to torque M1 for the lower
load-zone 16, and thereby increase misalignment, they have been
indicated as positive values.
[0023] The total misalignment M is the vector sum or combination of
the three components, M1 M2 and M3. As discussed hereinabove,
examination of upper and lower load-patterns in used bearings has
determined that, when the bearing is loaded in its upper load zone
(FIG. 2A), the total misalignment M is approximately zero, since
the load pattern is centrally located. Thus:
M=M1-M2-M3=0,
[0024] which means that:
M1=M2+M3.
[0025] For the lower load-zone (FIG. 2B), for total
misalignment:
M=M1+M2+M3.
[0026] From the upper load-zone analysis, it is known that
M1=M2+M3, resulting in the conclusion for the lower load zone
that:
M=2.times.M1.
[0027] While for simplicity sake, the above analysis has been
presented as equations, it is to be understood that these are
actually vector approximations.
[0028] Referring now to FIG. 3, there is shown the bore profile of
the support bearing 30 in accordance with the present invention. In
the light of the above-analysis, the optimum bore-contour for the
support bearing in a vertical cross-sectional plane is described by
a horizontal or non-sloping line or surface 32 at top, or upper
portion, or half, of the bore of the bearing, since examination of
used bearings has shown that the load zone with such a
configuration is already substantially centered. It also follows
from the analysis described hereinabove that the optimum
bore-contour for the support bearing in a vertical cross-sectional
plane is a sloping line or surface 34 at the bottom, or lower,
portion, or half, of the bore, which slope is equal to the total
misalignment M, which is a correction of 2.times.M1, as described
above. The support bearing 30 is still provided with the flared or
conical ends 40, 42 as disclosed and discussed in above-discussed
U.S. Pat. No. 4,940,002. As mentioned above, for an eight-inch
truck axle, and a locomotive weight of between 60,000-70,000, M has
been determined to be approximately 0.001 inch/inch. Therefore, in
the preferred embodiment, the slope of lower surface 34 would be
0.002 inch/inch.
[0029] It is, however, to be understood that the slope of the lower
surface 34 of the bore 30 may be varied depending upon the type of
traction motor that is to be used, the weight of the locomotive,
and the diameter of the axle. However, in all cases, the slope of
the lower surface will be based on a combination of the three
factors M1, M2 and M3, which factors may change owing to these
variables of type of traction motor used, locomotive weight, and
axle-diameter.
[0030] Referring again to FIG. 3, the contour of the mid-section of
the interior bore 30' of the support bearing 30 may best be
described as a non-right, or acute-angle, cone, of which the center
section of the bore 30' is the frustroconical section of the cone.
This cone is uniquely defined by an altitude 40 having a slope of
1.times.M1 to the horizontal, and an apex angle equal to arc tan
2.times.M1.
[0031] While the above-description has been directed to a traction
motor manufactured by the EMD of General Motors Corp., the same
analysis and basic bore-configuration of the invention also applies
to a traction motor made by the General Electric Company. In the
case of the GE traction motor, the application thereof for use in a
locomotive of the same wheel spacing, same approximate range of
axle-loads, same general arrangement of bearings, gears and other
parts. The main difference is that the standard GE axle is 9" while
that for GM is 8", and that the GE bearing length is approximately
three inches shorter, about 9" for the GE bearing and 12" for EMD
bearing. Axial dimension of the GE wick and window is also,
therefore, correspondingly shorter. Moreover, in the GE case,
axle-bending M1 would likely be a little less on account of a
larger diameter axle. While this GE support bearing has a
convex-crowned central bore rather than a cylindrical central bore
as in the GM version, the end-relief sections are similar to the GM
version. This convex-crowned central bore may be reworked into a
cone with concave sides having a skewed axis for using the present
invention therewith.
[0032] The bore of the support bearing of the present invention may
have application in other areas and uses, such as the outer-ring
roller path of rolling-element bearings in the traction-motor
environment, and to both plain and roller bearings in other
traction motor applications with various axle diameters, axle
loading, and wheel gauges, as well as to both plain and rolling
element bearings in other applications, by making appropriate
adjustments for variations in types and additional factors in the
combination of shaft misalignment. These other potential
applications may include marine and mining equipment, power
generation equipment, construction equipment, and other heavy duty,
military, and industrial bearing applications.
[0033] While a specific embodiment of the invention have been shown
and described, it is to be understood that numerous changes and
modifications may be made therein without departing from the scope
and spirit of the invention as set forth in the appended
claims.
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